1. Field of the Invention
The present invention relates generally to prosthetic knee implants of the type commonly referred to as “mobile bearing.” More specifically the invention relates to mobile bearing knees for use in unicompartmental (“uni”) knee prostheses.
2. Description of the Related Art
Prosthetic knee implants having a bearing component that is movable relative to a fixed tibial tray during flexion and extension of a person's knee joint are known as mobile bearing knees and will be referred to as such throughout this document. Mobile bearing knees generally consist of a tibial tray affixed to a prepared proximal tibia and a bearing component which typically comprises ultra high molecular weight polyethylene (“UHMWPE”). The bearing component is adapted to allow a femoral component to articulate against the same. Often, there exists a mechanism or a plurality of mechanisms to restrict or limit movement of the bearing component relative to the tibial component during movement of the knee.
It has recently become a goal of physicians to perform orthopedic surgeries, such as knee arthroplasty, in a less invasive or minimally invasive manner. To this end, orthopedic surgeons have begun performing uni knee arthroplasty in situations where only one compartment of a patient's knee is affected by disease or trauma. Partial knee arthroplasty avoids causing trauma to the unaffected compartment of the knee. In addition, uni knee implants are smaller than total knee implants. Thus, partial knee arthroplasty is a naturally less invasive alternative to total knee arthroplasty. However, as uni prosthetic knee joints are less well known than their total knee replacement counterparts, few, if any, designs exist for mobile bearing uni knees.